Typewriting machine



A. A. JOHNSON.

TYPEWRITING MACHINE.

APPLICATION FILED AUG-30, 1920.

Patenfed Apr. 18, 1922.

ARTHUR A. JOHNSON, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO JOHN Q. SHERMAN, OF DAYTON, OHIO.

TYPEWRITING MACHINE Specification of Letterslatent.

Patented Apr. 18, 1922.

Application filed August 30, 1920. Serial No. 406,793.

To all whom it may concern:

SON, a citizen of the United States of America, residing at Washington, District of Columbia, have invented certain new and useful-Improvements in Typewriting -Machines, of which the following is a specification.

This invention relates to typewriting machines and more particularly to means whereby the webs may be fed around the platen of the machine by pins or other p0sitively acting feeding devices, by means of which the webs are maintained in accurate alignment and registration with each other during the feeding and writing operations.

Heretofore, it has been proposed to provide on, or at the endsof the platen, pinwheels having pins which engage through perforations provided in the side margins of the webs, said pin-wheels conforming substantially to the diameter of the platen. It has been found, however, that with said proposal the webs are torn at the perforations by the pins, and that with this form of feeding device it is, therefore, impractical, if not impossible, to so feed a plurality of superposed webs. The tearing of the webs at the perforations is due to the disalignment of the perforations into which the pins should extend when first engaging the webs, which disalignment is caused by the difference in the lengths of the arcs of the various webs between the points where the webs first engage or conform to the platen at the receiving side thereof and the point where the webs leave the platen at the delivery side thereof, which results from the radial distance of each web from the center of the platen being greater than the radial distance of the web directly beneath it from the center of the platen, due to the thickness of the web. Since, in ordinary typewriters of the rotary "platen type the webs are curved by contact or engagement with the platen for an angle of approximately 180, the disalignment or ofi-setting of the perforations is so great that the pins tending to engage the same at the receiving side of the platen cannot enter corresponding perforations in all the webs, the perforations in the top web being advanced too far from the corresponding perforations in the under-webs to permit a pin to simultaneously enter both perforations; conse- 'quently, the webs are torn by the pins.

I have found, however, that, if the pins of the pin-Wheels are so arranged as to engage the webs for a relatively short distance while the webs are curved around the platen, the ins will properly feed the webs without lia ility of the webs being torn,

while maintaining the webs in the properv alinement and desired registration relative to each other and to the platen.

To do this, I employ pin-wheels which have a diameter 'materi'ally less than the' diameter of the platen and so arrange the position of said pin-wheels that they will engage the perforations of the Webs for only a portion of the distance wherein the websconform to or engage with the platen. In

pins, arranged according to the present in-' vention, first engage the perforations being correctable and being corrected by the pins as they engage the perforations and feed the web's.

I prefer to arrange the pin-wheels so that the" webs are engaged thereby at the writing line, whereby the webs are firmly held by the pins against relative movement during the writing of a line, the arrangement being suchthat the off-set of the perforations is corrected at the writing line. this pur ose, I mount the pin-wheel for rotation about an axis located forwardly of the axis of the platen and in the same horizontal plane as the platen axis and the Writing line.

I find it advantageous to rotate the platen in the usual manner, so that the web having direct contact therewith, will be assisted in its advancing movements by the rotation of the platen, and so that the wear of the platen will be substantially evenly distributed, as

in the ordinary typewriters. In this case,

it is preferable that the pin-wheels be given a feeding speed equal to the feeding speed of the platen, and that this be done bysuitable gearing between the platen and the pinwheels, whlch gearing I have provided.

For

I provide a stripper for freeing the Webs I from the pins of the pin-wheels after they have passed the Writing line sufficiently, and have also provided means for holding the webs to the pins in the vicinity of the writing line.

An extremely important feature of this invention is the specific means by which it is carried out. The structure may be economically and easily applied to'typewriting machines by merely removing the standard platen and the feed rolls and substituting the structure ofthe present invention, as a unit, means being provided for engaging some part of the carriage or platen frame structure, so that parts of the-structure of the present invention will be held stationary relative to the rotation of the platen. The means for holding the webs to the pins in proximity to the writing line may be easily substituted for the usual paper fingers of ordinary typewriters;

Other features and advantages inafter appear.

In the accompanying drawings Figure 1 is a side elevation showing the structure of the present invention, and a means whereby the present invention may be carried out;

Fig. 2 is a front view of the parts shown in Fig. 1, the pins at one side only being shown and the platen being broken away;

Fig. 3 is a top plan view of the present invention as applied to the carriage of an Underwood typewriter.

In an ordinary typewriting machine (an Underwood typewriter having been taken by way of example in. describing the present invention and its application to commercial typewriters), the type 10 swing upwardly and rearwardly to strike against the front face of a platen 11, which is secured to an axle 12 journaled in bearings in the platen frame of the paper carriage 13 of the machine. The axle 12 extends, as a rule, through the platen and protrudes from the frame 13 where it is provided with the usual handles 14, by means of which it is rotated. The platen is also rotated for line-spacing by the usual line-space mechanism 15, diagrammatically indicated by the usual line-space handle, which operates a pawl engaging a ratchet secured with the platen axle. The work-sheets are introduced to the platen across a paper table 16, and are guided by av paper apron 17".

In ordinary typewriting 'Inacltines, the work is held to the platen to be advanced thereby by means of friction rolls, spring pressed against the platen and located on-the under side thereof. As is well-known in the art, a plurality of separate work-sheets, when fed in this manner by feed rolls, creep relatively to each other, and therefore do not maintain accurate alinement and registration as the worksheets advance. When will herethe work is in the form of continuous strips or webs, this creep is accumulated and is extremely disadvantageous, making the simultaneous use of a plurality of continuous webs impractical in many instances, particularly where the webs are printed or ruled in advance.

According to the present invention, separate continuous webs can be advantageously employed, since the feeding of the webs is a positive action, and the creep thus overcome. Further, according to this invention, the offsetting, due to the curvature of the platen, is also overcome. This is accomplished by feeding the webs positively by means of pins 17 which enter and engage perforations 18 in the webs and feed the webs across the writing line in unison,-when rotated; the perforations and the printing of the individual webs corresponding, and registering when superposed, one set of pins 17 and perforations 18 being provided for each side margin of each web.

As has been above stated, the pins 17 engage the webs for a portion only of the distance wherein the webs conform to the contour of the platen. To do this, I mount the pins 17 of each side set upon a wheel 19, whose diameter is materially less than that of the platen 11, and position the wheel 19, as shown in Fig. 1, so that a limited number of the pins 17 will be in position to engage the webs carried by the platen, the remainder of the pins being located beyond the range of the webs. The pin-wheels 18, being located forwardly of the axle of the platen, cause their pins to engage the webs in the vicinity of the writing line, and thus the webs are held bythe pins during the writing of a line.

In order that the structure of the present invention may be easily applied to typewriters of commerce, I provide each pinwheel 18 with a supporting plate 20 having an aperture 21 to permit the plate to be slid over the end of the platen axle 12, and whereby the plate and the parts carried thereby, are supported by the platen axle in proper position relative to the platen and to other parts of the machine.

The pin-wheel structure at one side of the machine is merely a duplicate of the pin-wheel structure at the other side of the machine, therefore the following description will be directed to one of said pin wheel structures.

The pin-wheel 19 is supported for rotation on a bearing 22, provided upon, or formed integral with, the supporting plate 20. the aperture 21 for the platen axle extending through the bearing 22, since the bearing must be so located that the pin-wheel 19 may rotate Without interference with the axle 12. The pin-Wheel 19 is held to the bearing 22 by a disk or washer 23 which,

- movement.

in turn, is held to the bearing by a screw 24 threaded into the bearing and having a head impinging against the washer 23. The plate 20 is held stationary relative to the platen by a lug 25 extending upwardly therefrom, which is provided with a hole 26 through which the usual paper finger rod 27 is adapted to extend, so that said rod 27, which is stationary relative to the rotation of the platen,.will hold the plate against This arrangement of holding and mounting the supporting plate 20 by means of the platen axle 12 and the paper finger rod 27 permits the plate to be slid along said rod and axle to proper position.

The lug 25, in the structure illustrated, is in position to engage the paper finger rod of an Underwood machine, but it will be understood that it is not limited to this particular form or position, it being merely necessary that the plate be provided with some means for holding it stationary relative to the rotation of the platen. The supporting plate may be held against movement longitudinally. of the platen 'by any suitable means, for instance, by a disk or collar at one side and the platen on the other side.

The supporting plate is provided with a shield 28 for holding the webs out of accidental engagement with the pins 17, except at the proper time in the course of the feeding of the webs. This shield may be formed integral with the plate 20, or it may be a separate piece attached thereto by any suit able means. Preferably, the shield 28 conforms to the general contour of the platen, so that the supporting plates can be conveniently mounted on the platen axle without interference from other parts of the machine.

As has been above stated, it is preferable, according to this invention, that the platen and pin-wheel have the same, or substantially the same, feeding speed, but the pinwheels have a smaller circumference than the platen. Therefore, in order that the same line space mechanism which is found in commercial machines, can be employed, without change, to rotate the pin-wheels, and so that the pin-wheel and platen may have the same feeding speed, I provide gearing between the platen axle 12 and the pinwheel 19, of the proper ratio of transmission. The gearing comprises a gear 29 secured to the platen axle and rotated by the usual line-space mechanism and at the same angular speed as the platen; a gear 30, mounted to rotate on the supporting plate 20 and meshing with the gear 29; a gear 31 of larger pitch diameter than: the gear 30, but secured thereto; and a gear 32 meshing with the ear 31 and secured to the pinwheel. Thus, the pin-wheel is rotated in the same direction and at the same periphadapted to pass.

'eral speed as the platen. The gears 30 and 31 are rotatably mounted upon a shouldered screw 33 threaded in the supporting plate 20. The gear 29 is preferably mounted at the outside of the supporting plate, and, of course is secured to the platen, and therefore serves as a means for holding the supporting plate. and the mechanism carried thereby against movement and close to the platen 11.

At the delivery side of the platen, 1 provide a stripper 33, which may be mounted upon the supporting plate 20, or formed integral therewith, and which is provided with a slot 34, through which the pins 17 are The part of the stripper located at the side of the slot 34 engages the webs and causes the webs to be raised from said pins and to travel upwardly therefrom.

The webs are held to the pins 17 at, or close to, the writing line, by means of fingers 35 having slots 36 through which the pins 17 are adapted to pass, and having portions 37 adjacent the slot, adapted to lie close to the webs. The fingers are carried upon the paper finger rod 27 and in reality -replace the usual paper fingers. The fingers may be provided with a bifurcated bearing or other suitable means, 38, which straddles the supporting plate 20, whereby the fingers are always held in a predetermined relation to the pin-wheels 19 and the pins 17 carried thereby. The fingers may be mounted upon.

the rod for rotation thereon, whereby the fingers may be swung upwardly away from the webs, when desired, and they may be held in operative and in inoperative positions by means of a detent 39.

At the ends of the platen, just outside of the pin-wheel mechanism, there may be provided a relatively narrow auxiliary platen secured to the platen axle.

Variations may be resorted to within the scope of my invention, and portions of the improvements may be used without others.

I claim as my invention:

1. In a typewriting machine, the combination of a platen; and pin-wheel feeding devices for feeding superposed webs and main taining said webs in alignment, said pinwheel feeding devices adapted to engage said webs for a portion only of that portion thereof which conforms to the contour of the platen.

2. In a. typewriting machine, the combination of a platen; a platen axle; and pinwheel feeding devices comprising pinwheels having a smaller diameter than the diameter of the platen, said pin-wheels being mounted for rotation and being adapted when rotated to engage a portion only of that portion of the webs which conforms to the contour of the platen, to feed said webs and maintain the same in alignment.

3. In a typewriting machine, the combination of a platen; and pin-wheel feeding devices comprising pin-wheels having a smaller diameter than the diameter of the platen and mounted in position to engage the webs carried by the platen at the writing line and maintain said webs in alignment;

4. In a typewriting machine,the combination of a rotatable platen; pin-wheels for feeding webs carried by said platen and maintaining the webs in alignment during thet'eeding and writing operations, said pin-wheels being smaller in diameter than the platen and located at the printing line across the platen; means for rotating the platen; and means for rotating the pinwhecls concomitantly with the rotation of the platen.

In a typewriting machine,the combination of a rotatable platen; pin-wheels for feeding webs over said platen and maintaining the webs in alignment during the writing and feeding operations and located at the printing line across the platen; means for rotating the platen; and means for r0- tating the pin-wheels at a different angular speed from the angular speed of the platen.

6. In a typewriting machine,the combination of a rotatable platen; pin-wheels for feeding webs carried by said platen and maintaining said webs in alinement during the feeding and writing operations, said pinwheels being of less diameter than the diameter of the platen and located at the printing line across the platen; means for rotating the platen; and means for rotating the pin-wheels at the same peripheral speed as that of the platen.

T. In a typewriting machine,the combination of a rotatable platen; pin-wheels for feeding webs carried by the platen and maintaining said webs in alinement during the feeding operations, said pin-wheels being of less diameter than the diameter of the platen and located at the printing line across the platen; means for rotating the platen; and gearing between the platen and the pin-wheels whereby the pin-wheels are rotated by the platen at the same peripheral speed as that of the platen.

8. A pin-wheel feed structure for application to a typewriting machine, comprising a supporting plate; a bearing on said supporting plate; a pin-wheel mounted on said bearing; an aperture in said plate through which the axle of the platen of the typewriting machine may pass and whereby said supporting plate is mounted on said axle; and means for holding said supporting plate stationary relative to the rotation of the platen.

9. A pin-wheel structure for application to a typewriting machine, comprising a supporting plate; a bearing on said supporting plate; a pin-wheel mounted to rotate on said bearing; an aperture in said plate through which the axle of the platen of the typewriting machine may pass and whereby the supporting plate is mounted on said axle; shielding means onsaid plate; a stripper on said plate for removing the webs from said pin-wheels; and means for holding the plate stationary relative to the rotation of the platen.

10. A pin-wheel structure for a typewriting machine comprising a supporting plate having an aperture through which the axle of the platen of the typewritin'g machine is adapted to pass and whereby the plate is mounted on said axle; and a lug on said plate having an aperture through which the paper finger rodot the typewriting machine is adapted to pass. whereby the plate is held stationary relative to the movement of the platen axle.

In testimony whereof I aflix my signature.

ARTHUR- A. JOHNSON. 

